This invention relates to a novel process for the oxidation of methyl benzenes. More particularly, this invention relates to an improved process for the oxidation of methyl benzenes with air or oxygen in the presence of acetic anhydride and sulfuric acid under mild conditions to form a phenolic acetate and methylene diacetate. These compounds may then be converted to the corresponding phenolic compound and formaldehyde or paraformaldehyde by, for example, pyrolysis.
Earlier work of Grozhan et al., (Doklady Akad. Nauk, SSSR, 204, No. 4,872) established that acid catalyzed oxidation of toluene at high temperature and pressure in acetic anhydride followed by saponification of the reaction product gave phenol in modest yield. More recent work of Lyons, Suld and Shinn application Ser. No. 945,747 has shown that phenyl acetate, methylene diacetate and acetic acid are the major products of the acid catalyzed air oxidation of toluene in acetic anhydride. Despite recent improvements using catalysts initiators and promoters and acetic acid as a solvent this prior work has necessitated high temperatures and pressures to achieve reasonable rates and yields.